Control mechanism for dual camera shutters



March 1, 1949.

W. H. ROBERTSON CONTROL MECHANISM FOR DUAL CAMERA SHUTTERS 9 Sheets-Sheet 1 Filed Feb. 14, 1944 V INVENTOR A OR Y March 1, 1949. w. H. ROBERTSON CONTROL MECHANISM FOR DUAL CAMERA SHUTTERS 9 Sheets-Sheet 2 Filed Feb. 14, 1944 INVENTOR m,

TT NEY March 1949- w. H. ROBERTSON CONTROL MECHANISM FOR DUAL CAMERA SHUTTERS 9 SheetsSheet 3 Filed Feb. 14, 1944 J/ INVENTOR Q b BY TO EY March 1, 1949; w. H. ROBERTSON CONTROL MECHANISM FOR DUAL CAMERA SHUTTERS 9 SheetsSheet 4 Filed Feb. 14, 1944 now INVENTOR mm,

March 1, 1949. w, RQBERTSQN 2,463,206

CONTROL MECHANISM FOR'DUAL CAMERA SHUTTERS Filed Feb. 14, 1944 9 Sheets-Sheet 5 INVENTOR TO EY March 1949. w. H. ROBERTSON CONTROL MECHANISM FOR DUAL CAMERA SHUTTERS 9 Sheets-Sheet 6 Filed Feb. 14, 1944 INVENTOR March 1, 1949. w. H. ROBERTSON 2,463,206

CONTROL MECHANISM FOR DUAL CAMERA SHUTTERS Filed Feb. 14, 1944 9 Sheets-Sheet '7 INVENTOR A TURN Y Mam}! 1949. w. H. ROBERTSON CONTROL MECHANISM FOR DUAL CAMERA SHUTTERS 9 Sheets-Sheet 8 Filed Feb. 14, 1944 INVENTOR March 1, 1949.

w. H. ROBERTSON CONTROL MECHANISM FOR DUAL CAMERA SHUTTERS 9 Sheets-Sheet 9 Filed Feb. 14, 1944 M QFMI...

INVENTOR 1%1'T0ENEY Patented Mar. 1, 1949 GONTROL MECHANISM FOR DUAL CAMERA SHUTTERS William H. Robertson, Dayton, Ohio, assignor to The Globe Industries, Inc., Dayton, Ohio, a corpoi-ation of Ohio ApplicationFebruary 14, 1944, Serial No. 522,321-

13 Clahns.

This-invention relates to a shutter mechanism for acamera and more particularly to a high speed shutter mechanism permitting light to pass for an extremely short period of time.-

An object of this invention is to provide a shutter mechanism, wherein two shutters are used, one ofwhich opens the light passage and the other of which operates to close the light passage.

Another object of this invention is to provide a shutter mechanism for a camera wherein the shutter mechanism has a period in which to accelerate before actually beginning to open the light passage.

Another object of this invention is to provide a pair of shutter mechanisms, one of which is used for opening the lightpassage and the other for closing the light passage, said shuttermechanisins eachhaving a movement through which the mechanism is accelerated before beginning to open and close the light passage, to thereby rapidly open and close the passage.-

Another object of this invention-is to provide a pair of shutter mechanisms, one of which opens the light passage and the other closes the light passage, eachof saidshutter mechanisms having an acceleration period prior to the operative movement thereof, one of the shutter mechanisms used in closing the light passage'beginning its acceleration period at a later time than the beginning of the acceleration period of the shutter mechanism'usedin opening the light passage, so as to permit unobstructed passage of the light for a short interval-of time.

Another object of this invention is to provide a control mechanism for a dual shutter device wherein the control mechanism causes both shutters to operate simultaneously during the exposure of the film and causing the shutter devices to operate inv seriatim when resetting the shutter mechanism, so as to first close the open shutter before openingthe-closed shutter to restore each of the shutters to their home position in readiness before-exposingthe succeeding film without admitting light to the film chamber.

Another object of this invention is to provide a delayed action mechanism for a dual shutter control ciacamera, said delayed action mechanism being adjustable so as to cause the shutter closing the light passage to begin the closing thereof at a predetermined interval of time after the shutter opening: the light passage has completely opened the-light passage. p

Another object: of this invention is to provide 2 a spring motor for a shutter mechanism wherein the spring motor functions as a shock absorber at the end of the operative movement.

Another object of this invention is to provide a dual shutter mechanism and an iris mechanism mounted between the lenses of a camera.

Another object of this invention is to provide a housing for the lenses, a dual shutter mechanism and the iris, so that one lens and one shutter mechanism are positioned in each half of the housing and may be separated for inspection, repair, et cetera.

Other objects and advantages reside in the construction of parts, the combination thereof and the mode of operation, as will become more apparent from the following description.-

In the drawings, Figure 1 discloses a diametrical cross sectional view of a lens housing, the lenses mounted therein and an iris mounted between the lenses, adapted for use in a camera.

Figure 2 is a side elevational view of a housing similar to the housing shown in Figure 1, with parts broken away to show some of the actuating mechanism for a dual shutter mechanism built into the housing shown in Figure 1.

Figure 3 is another view of the housing shown in its camera support, with parts broken away to show some of the actuating mechanism.

Figure 4 is another fragmentary view of'a portion of the housing, with parts broken away to show apart of the actuating mechanism.

Figure 5 is a transverse cross sectional view takensubstantially on the line 55 of Figure 2, showing the shutter blades or leaves in closed position.

Figure 6 is another cross sectional view taken substantially on the line 6--6 of Figure 2, showing the shutter blades or leaves in open position.

Figure 7 is a fragmentary sectional View of a portion of the actuating mechanism. 7

Figure 8 is a view similar to Figure 6, showing one of the shutters immediately after exposure.

Figure 9 is a View similar to Figure 5, showing the shutter shown in Figure 5 immediately after exposure, that is, in open position.

Figure 10 is an exposed View of the spring motor assembly.

Figure 11 is an enlarged detail view of the motor assembly and a shutter leaf.

Figure 12 is an enlarged view ofthe linkinterconnecting the motors.

Figure l3 is an enlarged fragmentary view of theringinterconnecting mechanism.

Figure 14 is a fragmentary sectional viewof 3 the device disclosed in Figure 13, showing a side elevational view thereof taken substantially on the line l4-l4 of Figure 15.

Figure 15 is another fragmentary sectional view taken substantially on the line I5l5 of Figure [4.

Figure 16 is a fragmentary perspective view with parts broken away to show the adjusting cam in a position different from the position shown in Figure 14.

In Figure 1 the housing assembly has been shown in cross section to show the arrangement of the lenses and the position of the iris without the shutter mechanism.

Referring to the drawings, the housing assembly includes a pair of end members 20 and 22 and a pair of cylindrical spacing or supporting members 24 and 26. Members 20 and 24 are used in supporting one of the shutters and members 22 and 26 are used in supporting the other shutter. This housing assembly may be separated into two halves, one of which constitutes members 26 and 24 and the other constitutes members 22 and 26. The half of the assembly including members 20 and 24 has been shown in Figure 5 and the other half of the assembly including members 22 and 26 has been shown in Figure 6.

As may best be seen by referring to Figure 1, member 20 is provided with internal threads, threadedly engaging an annular lens supporting member 30, supporting a lens 32, which is held in position by a threaded collar or retaining member 34. Member 22 is also provided with internal threads, threadedly engaging an annular lens supporting member 36, supporting a lens 38, which is held in position by a threaded collar or retaining member 40. Member 36 is provided with internal threads that support a second lens supporting member 42, supporting a lens 44, held in position by an annular ring 46. It is to be noted that a considerable space is found between the lens 32, supported in one-half of the housing, and the adjacent lens 44, supported in the other half of the housing.

The pair of annular spacing and supporting members 24 and 26 are mounted between members 20 and 22. Member 24 is provided with an apertured partition 54 and member 26 is provided with an apertured partition 56. The apertured partition 56 supports an annular ring 58 supporting the iris 60 and the associated mechanism. The structure shown thus far is illustrative of the lens mountings and the positioning of the iris between the lenses. As may be clearly seen in Figure 1, there is a clearance between the iris 60 and the lens 32 and there is a clearance on the other side between the iris 60 and the lens 44. These two spaces may be utilized for a pair of shutters, one shutter for each space. The disclosure in Figure 1 has merely been shown for the purpose of describing the structure of the lens supporting mechanism and the iris supporting mechanism before inserting the shutter mechanism which has been incorporated into the structure, as will appear more fully from the description that follows. The disclosure in Figure 1 is illustrative of the lens supporting mechanism without being limited to this particular type of mechanism.

The shutter mechanism includes two sets of shutters, one of which is moving into open posithat the shutters emit light for a predetermined period of time. The mechanism for controlling the operation of the shutters is so constructed and arranged that the shutter actuating mecha- 5 nism upon being reset, will operate in seriatim, so as to first close the shutter which has moved into open position before beginning the opening of the shutter that closed the light passage at the end of the exposure. The leaves or blades used in opening and closing the aperture overlap, so as to accelerate before making an exposure and are driven by individual motors, so that a light weight, quick acting, spring motor is used for each of the blades, rather than a heavy, large motor actuating all of the blades simultaneously, as will appear more fully from the description that follows.

Each shutter includes a plurality of blades Illlla and I001). In the embodiment shown herein five blades are incorporated into each shutter. As may best be seen by referring to Figure 5, the blades of one shutter that is normally closed in readiness for another exposure overlap each other a distance A-B. In Figure 6, the blades of the other shutter normally open and in readiness to terminate the exposure, have been shown in open position. In Figure 6 it can readily be seen that the blades must travel a distance C-D before they begin to close the opening through the iris. The distance that the blades travel before beginning to close the opening through the iris depends upon the size of the opening in the iris. As is well known to those skilled in the art, the size of this opening varies from time to time, depending upon the setting of the iris at the will of the photographer. As may best be seen by referring to Figures 10 and 11, the leaves or blades I are individually mounted and driven by a motor mechanism that will now be described.

Individual motor mechanism The actuating motor mechanism for the shutter blades moving into open position when making an exposure and the motor mechanism for actuating the other set of shutter blades into closed position are identical with the exception of the angular position of the blades or leaves. That being the case, only one motor mechanism will be described. Wherever it is found feasible for the sake of clearness, the reference numerals pertaining to the motor mechanism for opening the shutters will each be followed by the letter a and the reference numerals pertaining to the motor mechanism for closing the shutters will each be followed by the letter b.

Figure 10 discloses an exploded view of the motor mechanism. Each blade of the shutter disclosed in Figure is mounted between a retaining plate "12a and a retaining plate l04a attached to a tubular member lllfia. A cam following member Him is also secured to members I02a, IUUa and Ma by a plurality of rivets H 2a. These parts are riveted together into a unitary structure and rotate in unison. Member lllla is provided with an axially disposed lug H411 located beyond notch 6a found in member 8a integral with or fixedly attached to a tubular sleeve member I2Da, having spline-like grooves or notches 122a in the end opposite member 811. The lug l |4a projects beyond the notch 6a and has limited oscillatory movement, as will appear more fully later.

A collar 130a, provided with a pawl [3%, is rotatably mounted on the tubular sleeve member mm. This collar [30a is provided with an aperposition.

ture I 34a receiving one end (not shown) of a motor spring I38a having its opposite end I4lla projecting into an aperture I420, in the splined collar I44a seated on the end of the tubular sleeve member mm. The spring I38a may be wound or tensioned by properly positioning splined collar member Na in the grooves I22a, so that the pawl I32a abuts the lug II4a, tending to rotate the lug I I4a in a clockwise direction, as viewed in Figure 10. The leaf and the motor when assembled are mounted upon a stud I5Ila having screw threads I52a threadedly engaging member and the extreme end of the stud I50a, that is, the reduced end I54a is seated in an aperture in the apertured partition 54. Stud member I50a forms a pivot or an axle, about which the leaf is operated.

The motor assembly is mounted partly within a semi-circular flange member I36a held in fixed position with respect to the housing by a screw I39a. This flange member I36a has an arcuate stop projection I3'Ia extending into the slot Ga and normally disposed in the slot So. The member I36a is attached to the partition 54 by means of the bolt I39a.

The motor spring I38a functions as a.. motor and as a shock absorber. When the motor has been wound and then released, as more fully described hereinafter, the spring I'38a actuates the collar I30a having the pawl I32a engaging the lug II4a integral with member lllla riveted to the blade II'II'Ia. Referring to Figure 11, the blade I000, is rotated in a clockwise direction at an extremely high rate of speed when making the exposure.

When the blade I00a approaches the open position, the spring I'38a. ceases to function as a motor, and instead, functions as a shock absorber, which will now be described. The lug I3la is stationary and is mounted in the slot IIIia.

Member 811 is biased in a counterclockwise direction, as viewed in Figure 11, by the spring I38a. Member I30a, mounted for rotary movement on the sleeve mm, is biased in a clockwise direction by the spring I38a.

The blade I IIIla is rotated in a clockwise direction, as viewed in Figure 11, until the lug I No engages the shoulder II9a. About that time the shoulder I 33a is moved into contact with the projection I3Ia. The .lug II4a is then clamped between the shoulder Il 9a and the pawl I32a, so as to arrest the movement of the blade in this It will not continue to rotate in a clockwise direction by virtue of the shoulder I l9a arresting the movement of the lug II4a. The blade will not tend to oscillate in a counterclockwise direction, for the reason that the pawl I32a follows the lug I|4a, so as to clamp the lug Il4a ..tions as a shock absorber, for resiliently arrest- :.-ing; the movement of the blade 100a. P

The motor mechanism that has been described thus far has been described in connection with the shutters that are moved to open position during an exposure. As stated above, a pair of shut- 5 ters normally in open position terminate the exposure by moving into closed position. Spring motors are used for closing these shutters. The spring motors used for closing the shutters shown in Figure 6 are identical to the spring motors described above, excepting the relative position of the motors with respect to the blades or leaves, which motors are identified by the sufiixes b in the reference numerals. The spring I38b is so tensioned that as the pawl I801) releases the spring, the blades IUIlb snap into closed position.

All of the leaves of one shutter mechanism operate in timed relation by means of a release and synchronizing mechanism, which will now be described.

Release and synchronizing mechanism The sprin motors actuating the blades IUIJa are released simultaneously by a suitable trigger mechanism used in releasing the pawls IBM.

This trigger releasing mechanism includes a motor control ring IIIia that is rotatably mounted in close proximity to each of the motors actuating the blades IDOa. Each of the spring motors actuating the leaves IflUb into closed position are released by a similar trigger mechanism, driven by a suitable spring mechanism in timed relation with respect to the releasing mechanism for the blades IOIIa. Means have been provided for correlating the movements and the timing of the two release mechanisms, as will appear more fully from the detailed description thereof.

In Figure 5 the leaves or blades IUOa are shown in closed position. The ear or extension IGUa of the cam following member I'IOa engages a re- 40 storing member I62a fixedly attached to the ring I'IOa extending into close proximity to each of the motors and journalled within the housing for the lenses. This ring Him is provided with a flange engaging a plurality of circumferentially disposed rollers I'I2a which form roller bearings for the ring.

When restoring member IGZa on the ring I'IOa actuates the ear Ia into the position shown in Figure 5, a pawl I80a engages a notch IBM in the ear I 84a of cam following member Ilfla. As best seen in Figure 2, the pawl I8lla is mounted upon a sleeve I86 journalled upon a pintle I88 and held in position by a suitable screw I90 and attached to a suitable boss I92 projecting inwardly from end member 20. Pawl IBM is provided with a lug I54a having fixedly attached thereto a stud I96a having attached thereto a spring I98a carried upon a pin 200a fixedly attached in the end frame member 20. The spring 198a tends to rotate the pawl members I80a in a counterclockwise direction, as viewed in Figure 5. Pawl members I80a are each provided with an extension 204a overlying the ring IIOa in the path of a stud 206a pivotally mounted upon the ring I'IIIa.

A like mechanism is used in releasing the spring motors shown in connection with the blades Iflllb used in terminating the exposure. The motor control ring I'lIlb shown in Figure 6 carries the release mechanism substantially identical to that described in connection with the release mechanism and the ring I'IIIa shown in Figure 5.

The rings I'Ifla and H01) are biased in a clockwise direction, as viewed in Figures 5 and 6 respectively, by helical springs 2lIIa and 2I0b reaecaaoc spectively. The lower lrin'g l llla, that is, the one shown in Figure 5, is held in the position shown by a pawl 2l2 pivotally mounted at 2M and engaging a detent i2lfi fixedly attached to the ring 110a. The upper ring 110b, :shown in Figure 14, is held in the position shown by a downwardly projecting lever or L-shaped bracket 220, having'an eccentric-cam 222 engaging apawl 224 pivotally mounted at 226 and biased in a clockwise direction, as viewed in Figure 13, by a helicalspring'228. The radialmovement of the 'pawl 224 is limited by a suitable stop, not shown, so that the spring 228 cannot rotate the pawl 224 beyond the eccentriccam 222. The bracket 22B, .the eccentric cam 222 attached to the bracket and the pawl 225 cooperate to hold the upper ring in locked position. The eccentric cam 22-2 isadjustableso as to adjust the relative position of the two rings l'lna and Hill), thereby'changing the time of the exposure, as will appear more fully later.

By oscillating the pawl 2l2 in a counterclockwise direction, as shown in Figure 5, the ring Him, that is, the ring shown in Figure '5, is released. .The two springs 216a cooperate torapidly rotate the ring lll'ila in a clockwise direction, as :shown in Figure 5, until the studs 266a engage the extension 28 3a on the pawl ifilla, so as to clear the notch 182a, thereby permitting the motor springs I381; to rapidly open the leaves tlilia, :so as to admit light to the camera, not

shown. Reference is 'now being made to the .leaves disclosed .in Figure '5. The lower ring iliia, disclosed in Figure 5, will continue to rotate in a clockwise direction under the influence of the springs '2llla until the stops 230 on the ring liila engage the stops 232 on the housing. Shortly before the stops 236 engage the stops 232,=the extension 238 .o'fthe pawl 22 will engage a roller 236 rotat-ably mounted in the housing, so.

.as to actuate the pawl 224 in a counterclockwise direction to clear the eccentric earn 222. This will permit the upper ring limb, shown in Figure =-6, 'to continue its rotation until it is arrested by 'a stop mechanism which includes the extension 234 on the ring llfib engaging the stop 23fi.

The actuating springs 2l0a and Zlfib may be identical and tensioned the same. In the absence of extraneous influences, this should cause the rings l'llla and Hill) to rotate at the same rateof speed. If the two rings ilter and H01) rotate at the same rate of speed, the relative time of exposure would then be dependent entirely upon the relative position of the rings Him and ll'li-b.

If these are so positioned that the distance from the releasing'stud '2ilta to the extension N ta is only slightly less than the distance from the releasing roller 28% to the extension 2951), the period of time for the exposure would be quite short. This iperiodof time may be increased by Y actuating theeccentric cam 222, so asto increase the distance from the releasing stud 2%bito the extension Ziidb, thereby causing a lag between the ring Wild and the ring Hilb. This increases the time of exposure.

In spite of the fact that the studs 236a, are equiangularly spaced on the ring 'l 'liia, and the pawls IBM are equiangularly diaposed, it does not necessarily follow, due to tolerances, that all the leaves will open in absolute synchronism. That being the case, it is desirable to have the leaves linked together so that all of the leaves will move in unison. A plurality of links 300 pivotally mounted at 302 and 3M interconnect theactuating mechanism oithe leaves so :that

none of the leaves :mayopen or close until the pawls 180a or 1801) have all (cleared .the notches 182a or 1821) respectively of the motors actuating theleaves-associated with one ring. ,In order that the leaves in Figure 5 shall open in:unison, itis first necessary for all of the pawls 180a to clear the notches l82a shown in Figure '5 :before the leaves can move. As soon as all of the .pawls lBlla have cleared the shoulders 182a, reach of the spring motors actuates its respectiveleaf into open position in synchronism with theother leaves. Slightly slottedconnection between the links and pins means that the links canonly be put in tension, never in compression. Therefore, these linkscan be lighter, due toslots.

In order that the leaves shall vmake a quick exposure, each leaf travels through the distance A.B shown in Figure 5 before exposure begins. During this movement the leaves are accelerated from zero speed to the speed acquired at this point. This permits the leaves .to travel at a high rate of speed fromthe time that exposure begins until the leaves have opened the entire open area of the iris.

It is equally important that the .leavesshown in Figure-6, which terminate the exposureattain a high rate of speed while traveling over the exposed area through the iris. The leaves are accelerated during the period that the endsof the leaves travel a distance equal to (3-D shown in Figured. During this period the leaves are accelerated to a high speed, thereby closing the opening very rapidly afterthe leaves begin to sweep across the exposed area through the iris. The leaves in Figure 6 for a short exposure may be in motion before the .leaves in Figure 5 have completed their travel, that .is, the leaves closing the aperture for a short exposure may have been accelerated by the time the leaves in Figure 5 have barely uncovered the aperture through the iris. For photographic workin airplanes traveling at high rates of speed at a relatively low altitude, it may be desirable to have an exposure of not more than of a second. This almost infinitesimal period of time necessitates accurate timing .of the shutter mechanism. It necessitates the acceleration .of both sets of leaves before reaching exposure and shutting position.

The two rings a and Hub rotating simultaneously permit accurate release-of the shutter tripping mechanism. These rings 1 10a' and Ilflb may be referred to as shutter tripping rings. The relative initial position of the ring "0a to the ring l'l0b may be adjusted. This-adjustment is accomplished by adjusting memberi3l 0 mounted on the side of the'housin'g and provided with a longitudinal slot receiving aro'ller' 3 l 2.pivotally mountedto the end of eccentric cam member 222. Member 3H] is provided with apairof vertically disposed slots, as best seen in Figure 14, one of which receives a screw 3|6 threadedly engaging a threaded stud 3H mounted in the side of the housing. The other slot receives a screw 3I8 having a sliding contact with member It'll]. By loosening'screw 3|6, member 310 may be raised or lowered. When it is raised, it will .oscillate the cam 222 'in'a counterclockwise direction,- as viewed in Figure 14. When it is lowered, it will oscillate the cam in a clockwise direction and into the extreme position shown'in Figure 16. The relative positions of the rings i l-0a and Hill) are thereby controlled.

Furthermore, the rate :of speed at which the ring l'lllb, shown..:in-.-'Figure 1.6, travels may be reduced by tensioning a spring 320 attached at 322 to the ring "01), shown in Figure 6, and tensioned by a cable 324 that may be fastened to an adjusting member 326 mounted for adjustment in a longitudinal bearing 328 and terminating in a crank arm 330 journalled upon a crank pin 332 fixedly attached in a disc 334 keyed to a stubshaft 336 provided with a control knob 338 resiliently held in any adjusted position by a helical spring 340. By rotating the control knob 338, the tension of the cable controlling the spring 320 may be adjusted, to thereby counteract the effectiveness of the spring, tending to rotate the ring l10b in a clockwise direction, as shown in Figure 6.

By increasing the tension of the spring 320, its effectiveness in retarding the rotary movement of the ring N02) is increased, so as to cause the ring I101) to rotate at a slower rate of speed, thereby delaying the trigger mechanism releasing the motors actuating the shutter leaf Ib shown in Figure 6, to thereby increase the duration of the exposure. The adjustment of the mechanism for tensioning the spring 320 is utilized to adjust the duration of the exposure. Tensioning this spring increases the time of exposure, releasing the tension of the spring shortens the duration of the exposure.

Shutter resetting mechanism In order to protect the film or plates used in the camera, it is first necessary to close the shutter that has moved into open position, that is, the shutter disclosed in Figure 5. The leaves l00a must be moved into closed position before opening the shutters or leaves l00b shown in Figure 6. As may best be seen by referring to Figure 3, the shutter resetting mechanism includes a shaft 350 journalled in a bearing 352 in the end member 20 and keyed to a gear 354 provided with a. stud or crank pin 356. The gear 354 meshes with a pinion 358 keyed to a shaft 360 having mounted on its opposite end a pinion 362 meshing with a gear 364 mounted for rotation upon an axle 366 fixedly attached in the end frame 20 or 22. The gear 364 is provided with a crank pin 368. By rotating the shaft 350, the gears 354 and 364 are rotated in unison.

As may be best seen by referring to Figure 3, the crank pins 356 and 368 are substantially 180 out of phase. A bracket member 310a is fixedly attached to the ring [1011. After exposure, the bracket member 310a has moved into engagement with the crank pin 356. The crank pin 368 does not engage the shoulder of bracket member 3101) fixedly attached to the ring I10b. It is to be noted that this ring has now moved in a clockwise direction, so that the bracket is in the dotdash position. Immediately upon resetting the shaft I50, by any suitable mechanism, the crank pin 356 will engage and actuate the ring I'I0a into position to reset the leaves I00a and rewind each of the springs I38a of the spring motors. The pawl 224 clears the cam 222, so that the ring I'I0a is reset without the pawl 224 engaging the cam 222 to reset the ring I'I0b. After the gears 354 and 364 have been rotated through substantially 180 from the position shown in Figures 5 and 6, the ring "0a and the leaves I00a actuated thereby have been reset to close the opening through the shutter. The crank pin 368 is now in position to engage the bracket member 31027, soas to actuate the ring I'I0b into exposure position and as this ring rotates, it resets the blades I00!) and rewinds the springs I362;

of the motors actuating the leaves I 001). The

brackets I62 engage the extensions I60 to rewind the respective motors associated with both shutters.

It may be desirable to open both shutters, so as to focus the camera. This is done when the camera is unloaded. This may be accomplished by adjusting a set screw 300 having its inner end 302 advanced inwardly so as to engage a shoulder or extension 234 mounted on the ring I'IOb. With the set screw adjusted into engagement with the shoulder 234, the springs actuating the ring 1101) are then ineffective. By this arrangement, it is merely necessary to release the pawl 2I2 permitting the ring I'l0a to trip the motors controlling the leaves I00a, so as to move these leaves to open position, without permitting the ring IHlb to trip the motors actuating the leaves I00b. From this it is clear that the leaves I002) remain open and the leaves I00a have moved into exposure position, that is, open position, in which event light fiows through the iris of the camera, permitting focusing and observing the view. After the camera has been focused or the view has been observed, the ring 410a may then be actuated by rotating the resetting mechanism, causing the crank pin 356 to actuate the ring HM and thereby reset the motors actuating the leaves I00a. The set screw 380 may then be unscrewed, so as to clear the shoulder 234, in which event the camera is in readiness to be reset for another exposure upon suitable plates or films being loaded therein.

For convenience of servicing, one shutter together with one lens, or one set of lenses are mounted in one-half of the housing. The other shutter and lens are mounted in the other half of the housing. The halves of the housing may be separated between members 54 and 56, so as to make each shutter available for adjustment, repair or inspection from the center of the housing. The halves of the housing are held together with suitable screws.

Although the preferred embodiment of the device has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts. the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claims.

Having thus described my invention, I claim:

1. A shutter mechanism for use with a dual shutter mechanism for a camera having one shutter for opening the light passage and a second shutter for closing the light passage, said shutter mechanism including a plurality of shutter leaves having an open position and a closed position, a plurality of individual spring motors one for each of the shutter leaves, means for locking the spring motors in wound position, said locking means including a plurality of trigger mechanisms one for each of the motors, means for releasing all of the trigger mechanisms, said last mentioned means simultaneously releasing all of the trigger mechanisms of one shutter, and synchronizing means for synchronizing the movement of the shutter leaves of said one shutter so as to cause the leaves to move in unison from one position to another.

2. In a shutter mechanism for a camera having a dual shutter controlling the light passage, each shutter consisting of a plurality of blades, the blades of one shutter being normally closed aeeazoe and". the blades of the other shutter: being normally open, a plurality ofi'nd'iVidiral" spring' motors, one for each of the shutter blades; the combination of a, pair of motor control rings'for releasi'ngthe motors. one for the motors of each of. the shutters, with means for interconnecting the ringsso as to hold the rings in a relatively fixed; position in readiness for exposure.

3'; In a shuttermech'anism fora camera having'a dual shutter controlling the light passage, each shutter consisting of a plurality of blades, the blades. of one shutter being normally closed and the blades of the other shutter being normallyopen, a plurality of individual springmotors,' one for each of the shutter blades, the combination of a pair of spring-urged control rings,. onefor. the motors of' each of the shutters, with adjustable means for interconnecting the rings so as to hold the'rings in a relatively fixed angular." position in readiness. for exposure, said angular positionbeing adjustable, upon the adjustment'of said adjustable means.

' 4. 111a shutter-mechanism for a camera having a dual shutter. controllingthe light passage, each shutter consisting of a plurality of blades, the blades of one shutter, beingnormally closed and the blades; of the other, shutter being normally open, aplurality of individual spring motors; one for each of the; shutter blades; the combination of." a pair of springeurged' motor control rings, onezfor-the motorsof each. of the shutters; with meansfor' interconnecting said rings, saidmeans including. a bracket member mounted upon one of the rings, said bracket member supporting; an adjustably mounted cam, and trigger means at' tached to the other ring normally engaging the cam to hold said other ring in a fixed relation with respect to the first ring.

5; In a shutter mechanism for a camera having a dual shutter controlling'the light passage,

each shutter consisting of a plurality of blades, the bladesof one shutter being normally closed and the blades of the other shutter being normally open, a plurality of individual spring, mo-

tors; one for each of the-shutter blades, the combinationof" a pair of motorcontrol rings, one-of said rings permitting the motors of one of the shutters to actuate its shutters'from closed position'toopeni position, the other ring permitting the motors off the other-shutterto actuate its" rality of blades,- the: blades of one shutter'being normally closed andtheblades of the other shutterbeing normally open, a plurality ofindividual spring motors, one for each of the shutter blades, aplurality of triggers one for each motorto hold the springs in tension, the combination including a pair'of trigger rings, a plurality of springs for rotating the rings, means for locking one of the-ringsrelativeto-the housingwith the springs in tension and means for interconnecting the otherrri'ngto the first ringso that as the first ring is released the second ring is also released t'ortl ereby releasethe triggers holding the springs tovpermit the motors to actuate the shutters;

72 In: a shutter mechanism for a camera having a housing for-a dual shutter controllingthe t2 lightipassa'ge; each shutter consisting; Of aplurality of" blades; the blades of" one" shutter being normally'closed and the-blades 'ofthe-other shut t'erbeing normallyopen a plurality of'individual spring motors, onef'or each of-- the shutter blades; a: plurality of' triggers one=for eachof the motors to hold the springs in tension, the combination including a pair of' trigger rings, a plurality of springs for rotating theringstdreleasethe tr-i'g gers; means for locking one-of therings relative toth'e housing with the springs-in tens-ion, means for interconnecting the other ring to the first ring so" that as the-, 'first ring" is; released thesecond ring'is alsorel'eased; and means for adjusting the rate of relative angular movement between the rings to thereby adjust the duration of exposure.

8': A camera shutter mechanism including: a housing separable into halves, one" lens being mounted in-one-half of the-housing and'another lens being mounted inlthe-oth'er half of" the housing; a'normail'yclosed shutter'mechanism mounted in one ofthehousi'ng halves, a normally open shutter "mechanism mounted inthe otherhalf of the housing; each of sai'd shutter mechanisms'ineluding a plurality of" shutter blades-and a: pl'u'- ral'ity of'spring motors, one for. each oftheshutter blades; said shutter mechanisms including a pair of trigger rings, one for eachoftheshutt'er mechanisms, said. trigger. rings controlling said shutter mechanisms, and means for synchronizing: the, movements of tlje trigger rings so that one; shutter mechanismopens: the lightpassage for an exposure and-1 the other shutter mechanism closes the light passageafter'the exposure.

9; A camera shutter" mechanisms including a housing" separable intohalves, one lens being mounted in: one -halfofth'e housing; and another l'ensbeing mounted in" the other half "of f the housing, a normally closed shuttermechanism'mounted in one of. thehousinghalve's; anormally open shutter. mechanism mounted in the-other half of the"housing',,eachof the shutter mechanisms-incl'uding' a plurality of overlapping blades'to) permit' acceleration thereof" before effecting the exposure and individual: otors for the blades; a pluralityof spring" motors, one for-each. of the shutter blades; trigger meansfor. releasably holding thei'spring, motbrs" in tensiomand means for synchronizing; the movements; of. the trigger means so" that} one shutter mechanism opens; the light passage for an. exposure and the other shutter mechanism closes the; light passage" after the-exposure;

10; Ina shuttermechanism' fora camera'having a dual shutter." controlling; the light' passage, each u r" cqn i' tina p r f" blade the" blades of" one" s hutter breiirg'r normally closed and the" blades of the" other shutter. being; normany open; a plurality, of individual springmotors; one'for eacht of'the" shutter blades, a plurality of triggers one, forreach of the motorsto hold" the springs-in tension; the combination" Of a pair of motor control rings" for releasing the triggers, onezfjoreachoftheshutters;,witlrmeans for" interconnecting the: rings" so as to; hold? the rings in a relatively fixed position. in readiness for exposure, meansifor'rotat'in'gtheringssoasito releasethe triggers; and; meansv for; adjusting the relative speed of rotation of the rings to thereby vary the exposure.

ll. A-dualshut't'er mechanismite: a. camera: including one; shutter" ior opening, the light passage and' a second shutt'erf'or closing; the. light passage, each; of said. shutters. including; a; pluralit'y of shutter leaves having an open position and a closed position, a plurality of individual spring motors one for each of the shutter leaves, means for locking the spring motors in wound position, said locking means including a plurality of trigger mechanisms, one for each of the motors, and means for simultaneously releasing all of the trigger mechanisms of one shutter, said last mentioned means simultaneously releasing all the trigger mechanisms of the other shutter in timed relation to the release of the trigger mechanism of the first shutter.

12. A dual shutter mechanism for a camera including one shutter for opening the light passage and a second shutter for closing the light passage, each of said shutters including a plurality of shutter leaves having an open position and a closed position, a plurality of individual spring motors, one for each of the shutter leaves, means for locking the spring motors in Wound position, said locking means including a plurality of trigger mechanisms, one for each of the motors, means for simultaneously releasing all of the trigger mechanisms of the first mentioned shutter, means responding to the first releasing means for subsequently releasing the trigger mechanisms of the second mentioned shutter, and synchronizing means for synchronizing the movement of the shutter leaves of each shutter so as to cause the leaves of each shutter to move in unison from one position to another.

13. In a shutter mechanism for a camera having a dual shutter controlling the light passage, the combination including two sets of shutter blades, the blades of one shutter being normally closed and the blades of the other shutter being normally open, two sets of individual spring motors, there being one set of spring motors for a set of blades, said spring motors of a set being arranged in a circular relation, synchronizing mechanism for synchronizing the movement of said spring motors, said synchronizing mechanism including a plurality of links for holding the motors in the same angular relation, each of said links having elongated slots, studs attached to the motor mechanism and projecting into the slots, said links interconnecting the motors in tension so as to prevent the movement of one motor at a faster rate of speed than the others so as to synchronize the movement of the motors, a pair of trigger means, one for each set of spring motors for holding the spring motors in tension, means for releasing one of the trigger means, and means responding to said releasing means for subsequently releasing the other trigger means so as to cause the blades to open and shut in timed relation to each other.

WILLIAM H. ROBERTSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 284,645 Little Sept. 11, 1883 516,861 Fawcett May 20, 1894 657,833 Reichenbach et al. Sept. 11, 1900 689,982 Morgan Dec. 21, 1901 1,377,366 Rose May 10, 1921 1,626,032 Fairchild Apr. 26, 1927 1,861,257 Barenyi May 31, 1932 1,865,078 Barenyi June 28, 1932 2,232,969 Ranft Feb. 25, 1941 2,344,382 Aiken Mar. 14, 1944 2,350,106 Fuerst May 30, 1944 2,359,116 Johnson Sept. 26, 1944 

